An insulating glass (“IG”) unit, or “IGU,” typically includes a pair of generally parallel panes, or “glazing panels,” held in a spaced-apart relationship by one or more spacers. The resulting open space between the panes, the “interior” of the IG unit, is filled with gas (including gas mixtures) such as air, or more insulative gas such as argon or krypton, for example. The insulating gas is typically sealed in the IG unit under ambient conditions, including atmospheric temperatures and/or pressures corresponding to a manufacturing location.